Grinding machine



June 24; 1930. H H. YERK Er 1,766,161

GRINDING MACHINE Original Filed Nov. 5, 1 925 6 Sheets-Sheet l June 24, 1930. H. H. YERK fr A.. 1,766,161

'r GRINDING MACHINE origina-F1166 Nov, 5, 1925 6 sheets-sheen 2 ma( fwrroxnev H.v H. YERK ET AL GRiNDING VMACHINE Original .Filed Nov. 5, 1925 6 Sheets-Sheet June 211930.' H. +1. YERK ET AL 1,765,161; l GRINDING MACHINE original' Filed Nov. 5, 1925 6 sheetsheet 4v ,nbr-royale),

June 24, 1930. y

H. H. YERK ET AL A GRINDING MACHINE June 2:4, 1930- H. H. -YERK ET Al. 1,766,161

GRNDN-G MACHINE A Original Filed Nov. 5, 1925 6 Smets-'Sheet 6 vkizrture and thevertical elevationof'thel i vided in the headstoclrs to causethe spindles and also toro-1 supporting tablepermit the work F, secured on the fixture, to be readily and Vacci'irately positioned relative to A spindle carried in spindle housing V21 eX- tends from the inner' end ofV each ofthe head-v stocks VvE, and'suitable mechanism` 1s proto *rotate about their own axes, Y tate bodilyl in an orbital path about axes eccentric'to the spindles. The opposed ends of I the spindles'carry grinding wheels 22 which,

l jferred to is fully described in the pending ap- August 7 1924.`

as shown, are of different sizes to finish the kbores iin the work F which are of different diameters. One type of mounting and driving'mechanism for .the spindles above replication for patent, vSerial No. 730,626, filed The 'headstocksi and 'their supporting frames D and C arereciprocated upon the bed of the machine, and the sides23 ofv the sup*- 'Y power Y housings may be moved. [Y A-bracket 24 (Fig.

" frames@ and D Vand -26 'are formed in Vsections portingframes extend below theutop ofthe walls of they the side walls of the machine`Y frame'are beveled complementary to maintain the frames in a uniformyhorizontal*plane, ovement machine frame. rIhe adjacent frame sides and of the reciprocal m in 'any position It will be'seen that the mech- 'ofthe frames. movable with the housings D and Crsothat can be transmitted in any position the ner end of each ,of the'headstockVV supporting l projects interiorlyof the machine frame.v upon each of the brackets 24 anda shaft26 extends, longitudinally-ofthe machine, from leach of the outer ends of the,v motors, shafts 26 are rotated thereby. These shafts end'sof the sections are connected byluniversal Y are'reciprocated,

` pulley Q36 carried of Y the spindle rotating, mechanisms.

the outer ends of-these ltwill be seen thatY the Y Amain driving motor 3,3 '(Fig) is rse'qured` of the machine"frame, j Vand power ,is .transmitted from a pulley l34 thereon byV a belt` 35 Lvwhich extends around a Y by a stub shaft'- securedV v 'to j the i rear i'wall'- g of theY lmachine lframe by bearingfbraclzet' The stubsliaft? has a adjacent V'to-'the rear Vpinion 39 securedithereto which meshes :with

i pinion 40 securediu*13011l .Shaftiflrwhch is theV gr inding wheeis.

f eccentric Yto the spindles'i Vanisms for axially'rotating the spindles arev v Y Y Y. a. rod which 4) 'depends 'from the in- Y A motor 25 Vis secured.

and Vthe;

andthe adjoining permit movement' without the possibility o rotatably secured inbearings 42 and 43.l cone pulley y44 is secured upon the shaft 41 intermediate the bearings 42l and43, and an'- Y other cone pulley 45 is secured upona shaft f 46 which is parallel to shaft by thebearings47 and 48. The conepulleys are of a similar shape,`beingfpositioned reversely relatively so that theirperipheries j spaced.l Abelt 49V ,75

are parallel. andslightly (Figs. Band extends around lthe lower cone pulley 45. rlhe cone pulleys 44 and 45 are so positionedv in relation to each other that.'

the belt 49 in passing between them engages 41 and is .carried bethV cone pulleys .frictionallyv The uppen i cone pulley 44 which is :driven ata constant speed from thus drives the lower cone pulleyv by frictional contact through the dependent upon the relative diameters of the cone pulleys where the belt 49`passes between them. Y

The lower cone pulley power'for actuating thel belt 49 at arspeedv the motor 33` as above described Y transmits the 1 y table'rv reciprocating mechanism and the mechanism for Yrotating f orbital` path about axes 'It will therefore be'seen that such mechanisms are' driven at a rate of speed which willremain constant for anyV particular setting' ofthe -Ybelt 49 but which maybe varied at will by the operator.i A yoke 50 is arranged'to straddle the belt 49 the spindles in an and is slidable longitudinally of the cones kon and by yolre, the speed of thelower driven cone 45 can be varied relative to the constant speed is secured in suitable bearings, i shifting the belt through means oftheV l at'which the cone 44 isy drivenfrom the motor.

Thus the speed of movement of the recipr'ocaj tion of Ythe headstocks and that n0f, the orbital` rotation of the spindles canbe varied asjdvl results can beobtained.

' rlhe variable speed drives the mechanismefor rotating the spindles in an;` orbital path, alsol drivesthe mechthat c'orrect speels to give th@J bestgndingl` Y c 'ci it sired toiinish bores of varying diameters Yso driven cone 45, which"V anism for reciprocatingthe headstoclrs, thus'V keeping 'aV proper relation betweentheheadf stock traveland the revolutions per:minutevr of the orbital 'movenientfof thewspindles.

ample, should the vance inch perl inch `per orbital revolutin'ofthe spindlea` even though the speed; ofi/orbital movement be vdiminished or increased. rlfhe mainte'f 125; Y

lizes the `fullfcapaci'ty ofthe VgrindingwheelsfV J Y nance of thisrela-tion of the` two drives uti-7 115, Such arrangementsimplifies the operators problem ashedoes not have to adjust thetim n,

ingV of ysuch movementsseparately. ForeX s l. headstoclsgbe vset to advv p j orbital revolution-of their ispindles, they Will continue to advance O5 Y Y j fovertaxing them,"as Y 1 a ccrrectrelationof thefspeeds of headstock r` f i travel' andY orbitalspindle rotationV must: be

maintained to remove'a maximum amount of 130` rstock and to: eliminate grinding Wheel breakdown 'or grindingwheel glazing. f l echanism isas'sociated with the belt'shitting yoke 50 so that it knowledge of the position of the belt between the cones necessary of I'rotation of extends around apulley 524 from which it passes aroundpulleys-Band 54 andthen o-ver thepulleysf'onthe shaft56. The cable through thefmachinefframe '15' frontfwall of the frame.l

passesffrom. the pulleys 55l transversely p and over pulleys 57 andiaround a drum 58 (Figs. 2 and 5 secured cna shaft Whichiextends through the A dial 59 issecured y tothefront ofthe machine frame and a pointer 6() is secured to the shaft :on which the drum 58'V lsecured. "By moving! thev pointer the cable :Willi-be moved, e thus'Vv shitting the yoke v Ybelt shifter, andY the relation fof' the'v pointer the machine. Yl Y te the; vdial'pyvill permitl the cable Atobe positione'd to cause the.lower-driving.;cone 45 to Y rctateat definite speeds, suchmechanism being operable 'by the operator vat the "front of' y anforbital path is actuated romthe cone pul- 67 isslidablykeyedto lthe shaft 64,y and a belt68 extends. therefroml around v a Vpull ey 69.

whichV is Hmounted upon afshaft rvfor transmit,- tingpovver `to operate the mechanism for rotating the grinding Wheelspindle inan 0r- 1 ing 711 `with which bita-l path: Af bracket y70. dependsY from the headstcck and is reciprocableltherewith;the

1 lower portionof such bra'cketfhavinga bearpulley 67 .is rotatably; connected .so that they can reciprocatetothe gather'longitudinallyofthe shaft ,64. '1

The' otherr end of the` shaftt46iis provided i with a'pinion'72 Which meshes 4vvitha pinion A'sliding .clutchV 7 5V 73 on acountershaftg74.` Y isl mounted upon the shaft 46.".y "Thepinion 72 isfdrivenfor remainsfidleupon operationfy oit'clutch75.` v Thecountershaft74 isvcarried inbeari-ngs74a and 74h. -Apulley76 isfslidajand a'r belt 177 VtransfV 76l f to pulley 78 bly keyed to the Vshaftp74'4 mitspower*` from pulley.

Y mounted upon a shaftilSOg( Fig. i2) ,connected paththc'fgrinding Wheelspindfle ofthe Lhead-V stockE. 1 Afbr'acket 79 (Fig.,3);is secured-,to

the headstock supportingrrame.Cpand is'pro-l Vided atitslower end withA the-bearing 80..in Which thehub `of the pulley 76 is rotatably mounted."y AsV the headstock reciprocates thel can be actuated fromv v the'frontf of the machine and With a definite to'cause ya definite speed' the driver cone.` A. cable 5l (Fig. 3) is secured atits ends to theiyoke and or together.

y cured on the outer ends of` driving-the i spindles in trolled by the stop mechanism 87 `Associated With mechanism 87 able Vstops 871 and 8 7" f nism is Well known in vention applies'.V "l f l of the shafts Qlarid mesh `With pulley 76'm0ves alongr the shaft'l74in'uni'lsonf.

'As `indicated'in Fig. 2the pulley 78 isjkeyed tothe shaftvl30 Which carries gear 131 enclosed in the housing '133' (Fig. 3),; Gear 131 meshes With gear 132 enclosed in the hous- Wheel spindle in an orbitalpath. v l f Y `-It 'will be seen'that 'the power from the* pulley v is' transmitted to either headstoclr when the clutches and 63 are engaged, and

that each clutch may be engaged or disen-V gaged at Will by the operator by means of' levers 86 (Fig. 1) whereby the headstocks can be reciprocatedindependentlyfof each other The ends ofV the: countershafts 64 and 'soi project beyond they ends of the machine 'Y frame, and-'pulleys' 66 are secured to the ends? f thereof. Countershafts 81 front ofthe machine adj acent the ends thereof and vare geared to reverse gearmechanism,` containedV in thel casings 82. gear mechanism is fully' described in U. S. Patent No. 1,633,060, issued June 21, .1927, to William J; Baumberger. Pulleys 83L are se- 66 by the belts`84.

vLink mechanisms 85' arefassociated With the clutches'75 and 63 vandare connected'to the llevers 86 at the front of the machine so power is transmitted thereto from the-pulleys vthat the operator can readily control them.

The reciprocation of the headstocks is conare adjust- 88 when the headstock reaches/'either end ofits stroke.l

extend along the Y The reverse' Y (Fie 1)- which engage' a lever Levers 88 cooperateivith'the re-l verse gear mechanism to cause theheadstock frame to change itsjdirection of longitudinal movement. The stop mechanism is adjustyableto permt various lengths of reciprocable travelV of the hejadstockr Such stop mecha- Power from the gearing in the reversegear 'casinzgs82' is transmitted through the bevell gears 89 (Fig. y5) which gears 90,'on the shafts p the inside lofthe front'V Wall ot the machine frame. Gear-s 92 are secured uponthejends 'gears93 on the the art to which thislinp mesh with' bevelY y Qluextendingadjacent'f` A;

shafts94"Wh`ichr extend insideof the end Walls of kthe machine: f Gears 95 .are secured on the rear ends of shafts 94 and vmesh with g'ears'96 Secured tothenends ofvshaftsf97- exteriorly of the reary Wall v 'of theimachine.` VThe shafts` .l l l l I 97 eXtendvintoboxes 98 Within veach of Which tothe Imechanism for` rotatingl in an orbitali.

change speed'gearingofconventional design 1s carried.' Thechange speed gearing boxes 5 98 are1securedtotherearvvall vofthem'achine frame and poweris transmitted therefromfby shafts 99 vtofvvorms v'1.00 in meshfvvith 70 lng 134 and serves to rotate' the grinding c i tu the shaftsy 81, and Y '2o Y aryonthe work table'10, whileV the headstocks of shafts '81.

103 which mesh with racks 104 sec-ured to der Y pending portions.

D and C. Worms100 and worm gears101 are enclosed'ingear housings 101a.

f The mechanisms in reverse gear afre driven from the Ydriving cone 45by` means 83,belts 84,. andfpulleys 66, connection is Vmade withshafts 64 rand 74, respectively.'

` -.'l[`hese'shafts` 164 and 74 are'driven from the rconepulley4, as previously described.4 The f reverse gear mechanisms in the'boXes 82 drive gears 108 through the change speed gearing,Y

7 thenfthe other,

as above described. Y v e Y It will be seen thatlthe stop mechanism 87 operates to cause the reverse gearing fto ro-V tate the pinion 103`first in yone direction and ciprocate `the racks 1.104 and the headstocl` frames Gand D. The work'isheld station'- the grinding wheels 22 reciprocate, carrying .the surfaces being back fand; forth over ground', `The headstocksiand their l'associ- -Y Y. with the headstocks'.- i351 49 longitudinally of beV driven at any headstoclr mechanism can desired speed within limited ranges.

"When the change Y speed gears in the casings 98 are thrown out of driving relation, `hand operated V rocate the headstocks C and D. Shafts105 (Fig. 2) extend transversely within themachine iframe and project through `the front wall thereof, VVand Yhave'hand wheels 106 (Figs. 2 and 5) securedthereto. Theshafts 105 are carriedby the bearings 107 and y gears 10,8 areseeured to-theinner ends thereof and racks 104. Y

' or" disconnect the pinions relation. therewith. Such vclutches are opertheshafts 10 and terminate inbuttons 112, exterior-ly ofthe 'hand'wheels106. YBy push-l `AV clutch 109 v with each power driven shaft 102 to lconnect 103V from driving VatedV by link lmechanisms 110 which are operated'by the rods`111 which eXtendthroughV ing the Abuttons11'2vin'l orpullingthem out,

. Athe "clutches'will operate"todisconne ct or 102. ,Wlh'enthe clutchespdisengage VVthe connectl the gears 103 relativeto the shafts f. Ypower'driven'mechanism from 'the' pinions .V5-103, the operator .can-.rotate either of the' y Y l hand wheels 106 ytofreciprocat'ey the associated Yileadstoek 'through the. gears 108V and 103.

ofthe Aheadstock frames'Y boxes 82 Y1924, mentioned abovei.

117 kserve to .counterbalance the weight ofthejpantograph inechy By means yof shafts 81, pulleys and that the pinions 103 rev' 'reciprocated either'b'y'power .or

mechanism can beutilizedY to recip-V l l y .opposite-ends. mesh with the vgears 103 which engage the'k/ Vment Y of the spindle, creases or decreases Y* cone pulley may In ,order Y to overcomev inequalities in the sion in each belt 80, a pantograph mechadescribed in the pending applicationy for patent, Serial No. 730,626,

Veightsll (Fig.

4) pivoted on arms at anism 115.

In Figs. 3 and filed August l7,

5V isshown aV water supply l; system for supplying coolingrwater to the` 'surfaces being ground, dueto varying tengrinding wheels 22. Al rotary Y pump 1118"VV drivenfrom shaft 41 by the ,belt-'119drawsf Y water by suctionthrough the pipe 120 from the tank 121 and Pipe 122 branches at plies water to the flexible hose pipes which leadinto and connectl withV .other flexiblerhosel pipes 125. Hosepipes 125 connect through suita- .the T 123fandv supdischarges itY into pipe 122.

1211 theinterior of the headstock` e5 ble couplings yto the 'ends of the spindlespar-V ried inv spindle housings 121, which spindles are hollow andprovidedfwith suitable open- V ings at'the lends thereof rwhere the grinding.

wheels 22 are attached. )Vith the* above Y simultaneously or individually. 'lhelhealdT when driven by power reciprocating vvmovement of Ltheheadstocks and the orbital movement' `of the Vspindles will be maintained at a definite speed ratio,

described; V .mechanism,` Y* A 'pworlrcan be positioned upon. thevmachine, if I andbores can befinished fromfopposite ends J as they are driven.fromthe cone45 andlsuch ratio of movement changed by shiftingthe belt 49,'and1in this p willnot be changed when i i the speed ofrotation rof the cone V45 is manner the 'proper relation of the headstockmovement and the speed of orbital move-V ment'of `the 'spindles isrmaintained to Vgive Y up the time 'required ltV will berseen,

thespeeds of the tabletravel and spindle` Y movements 4to suit Y they grinding machine rrto Y obtainjthe best resultsunder various conditions; Such change Vof fthe' ratio of speed is betweenl the table travel and .the bodily move the bestgrindingiresults.' It will 'thus be noted thatfthis machine materially speeds;

to inishfbores from Y herein Vthe latter 'inin'speed-when the .former` Y 1 howeven-that we have Y U provided,V means for changing` the ratios of-V is. Varranged in .association Vincreases or decreases inspeedr This latter relationship 'arises from the arrangement whereby mechanism for causingV longitudinal Inovement of the table'are'drivenfrom the same cone pulley,

the mechanism Vcausing the `bodily* yof the spindle Vand the" and the rate'of rotationo-f theAY be varied within relatively i f mechanism associatedwiththe coneA small amounts over a *relativelyy wide ranger,y

bythe operator bymeans of the belt shifting Vpulley mechanism as preivously explained.- j

" Itwill thus be seen that we havedesigned ay machine, in which oppositelyy disposed spindleshave their axes-inthe same plane and that'work with oppositely disposed bores can be ground lyasldesired.v ,j l

The bores preferablyshou-ld be ofthe same" diameter, as the orbital.'y movement-1 of the,

simultaneonsly or individual` j Vspindles is `controlledby acominon change speedjgmechanism.' However, if ya ,quantity of workis tobe ground withholes of rdifferent diameters, the speed lof orbital move?y ment of one spindle fcould be jchanged'by changingthe gearing on oneside oftheinaf bores not in alignment Espindles could be originally positioned to size, and both chine ,tol makev it slowerjor. faster. The orbital movement then would bethe correct one for the bores Vbeing ground. Of course, it will be seen that ifit is desired to grind a number of castings with oppositely disposed the headstocks and 1.x-In a grindingfmachine, inl combination,

, abase, a vertically adjustable bracket dis-y ,y 5ok and' beneath said work table, said hea'dstocks posed at therear side lof said base, said bracket extending over Athe top ofy said base l and in'spaced relationftheretof, a ywork'table mounted on said overhangingbracket por-v Y tion and adjustable transversely of said base, Y;

af pair of headstocksfmounted on .thetop of said base-'and slidable longitudinally lthereof' each having a-grinding wheelspindle extend?VVV ing outwardly toward thel opposed headli stock, independent y power units n carried` Y by each headstock for rotating said spindles on their respective axes, means operated fromv a common source of power lfor rotatingvsaidV spindles in orbital 'paths about axes 4eccenf'l tric to their own, `and, means operated from .the same ylast-mentionedisource of power for reciprocating said headstocks*longitudinally ofsaidbase. c' 1' 2. In a grinding machine,in combinatioiny a substantially open-top base, a xwork supporting table disposed substantially censpindles each extending outwardly toward' @stocks mounted onv said,

v thereof, brackets carried stocks longitudinally of trallyof saidlbase, said` table being{adju-stv.A Y i l able transverselyof said basexand vertically, f V` a c pair of 4opposed headstocks mountedon lsaid base and slidable longitudinally thereof, y A

saidA headstocks carrying grinding wheel the 'opposed ,headrstock,r said 1. vspindles vbeing vrotatableabout their ow-'ngaxes and about axes.

eccentricuto. their own, `said headstocks ex- I' tending downwardly into vsaid hollow base and each .carrying withingsaidbase, a motor,

means operatively connectedto saidmotor, for rotating said spindles at'relatively high;

speeds about their own axes at any adjusted` positions of said spindles withinY saidlieadf stocks, and jmeans ydriven from accminon source of power for.. rotating said spindles reciprocating said headstockslongitudinally of saidbase. Y,

a base,qa transversely and vertically adjustable` work supporting ytable carried by said base and disposed substantially [midway thereof, ya pair of oppositely disposedheadfstocks mounted on said base and"v slidable,

- longitudinally thereof,-giinding wheel spin'-y i dles carried by each headstock extend`V ing toward the opposed headstock, independent meanscarried by each headstock'vfor ro-g tating said tivelyon their own axes, y tending shaft disposed yadjacent o ne of said grinding wheel' spindles c respec-` i a longitudinallyex-` head'stocks, afpulleyvmountedfonsaid shaft; l

lin keyedfrelation thereto andy movable longi? tudinallythereof,lagbracket carried bysaidf headstock,fsaid pulley` being'secured to saidv bracket, means fory reciprocating said :headstocks longitudinally of saidV base,'means for rotatingsaidshaft, and driving meansa'sso ciated with said pulley and adjacent head-y stock whereby the grinding wheel spindle'on'Y said headstock may be rotated'y lin van'orbital;

path about an axis eccentric to its own dniing the reciprocation ofsaid headstocks.

In a grindingcmacliine, in combination, a base, a .transversely and vertically. adj ustable work supporting table carried'by 'saidw y base and. disposedl substantially .midway thereof, a pair of oppositely disposed "headlongitudinally thereof dies@ai-riefi` by each h means carriedv by each headstock forrotatingll a longitudinallyl extending:

4sl iaft {disposed adjacent eachzheadstock, -a A pulley.' .mounted on each said shaft'inkeyed,"

byeach headstock," l

relation4 thereto andI 'movable .longitudinally base and slidable .1 ,.grinding,wheel'spin` f l j eadst'ockextendingto@` wardtheopposed yheads'tockl` independent. .i j

f said grinding wheelspindlesrespectively on i l i their? ownv axes,

said pulleys being'securedtosai-d respective l brackets, meanspforreciprocating said head,l 1

rotating 'said'v shafts from' a, common'source said base, means for Y 139,

. Y. 85= 3. AIn a grinding machine, 'in combination,

Vit

ofl power,

:whereby each grinding wheel spindle `be rotated in an orbital path about an axiseccenq 'tricfto its own during thef reciprocation of fsaidfheadstocks, f. .Y Y

- 5.Y In a grinding'mac'hine, in combination, i

^ a base,'a work supporting table disposedfsubstantially'inidway offsaid baseandi adjustable vertically and transversely, a pair Y, of Y opposed headstocksmounted onsaid'base yandv reciprocable longi .i ing when Spinea-e ,Carried by'eaeh iieadsioek Y l and extending outwardly toward the opposed `j` j .Y '175 headstock, a motor carriedbyeach headstocli, means'carried bysa-id Vheadstoclrs and yassociated Vwithfsaid motors for rotating said spindlesjabvoiit their A,own axes, a pair of l shafts each extending cent. one of Isaid heads'toclts, a bracket `carried by and movable with eachsaid headstock, la

"and securedfto longitudinally Y adj apulley'jmountedon and in keyed relation to and movable longitudinally of each said shaft Y t said respective brackets, means operatively associated with eachsaidpulley and the respective' headstoclrfs to lrotate saidj grinding-.wheel spindles in Aangorbital path ,ed at will, and

Vabout an axis eccentricitoits own, a common drivingv `means :for rotating said shafts, adjacent said shafts ,where-V` be rotated ordisconnect-V Y speed changiilgmechanism a s,

clutches disposed byV said shafts may so'ciated .with said-common driving means ,g whereby the rotative speed ofsaid shafts may be controlled.V

t Y 6'; In y a grinding machine, Vin combination,- an` open-top"base, a pair fof oppositely;dis'` V; posed headstocks reciprocable on said base, a

7. vworlrsupporting table supported substan-V Yio tially midway i Vcarrying a grinding wheel spindle extending of said base, each headstock toward the opposedy headstock, independent l means for rotating said grinding wheel spinf dlesvon their own axes, alongitudinally dis-` posed rackfcarried by each headstock, shaftsV 'rotated from ya common -source v"of power,

"y 'means for rotating said spindles in orbital v mechanism for transmitting power yfromV said A, shafts to said respective 'headstoclrs`, whereby said Vheadstocks ina-yl be moved longit'udinaifV i' any iligeitherdireeiion-j base, a wo paths about axes,eccentrictotheir own from Ysaid respective shafts, pinionsY cooperatively `.associated with said racks to reciprocate said headstocks,` and means including reversing In a grinding machine, lanelongated opposed headstock, eachspindle being mountn Ved iii/its headstock for rotation `about its own v and aiviiigfmjeafis g's'eatawahf eachssaid pulley andr4 adjacent headsto'clr.

tudinally thereof, a" grindrk support" mounted l'on said base substantially midway between the ends there'-` of,a-p`air of opposed headstocks mountedfon said Vbase at opposite ends thereof and'V 'slid-'f i' able longitudinallythereof, each headstoclr` Y Y Vcarryinga 'grindingwheel' spindle which pro-' c jects from the inner endthereof toward the axis` mi about mi axis eccentric Yte itsowii,a motor 'carried byleach headstock,V means for? th'e'spindle with respect to said eccentric axis,

driving thespindlebfv each` headstock from lthe Vmotor on'the headstock iii all Vpositibni-i,ofv3,

a mechanism'forirotating each spindleabout its eccentric axis, a mechanism for reciprocat:l

ing leach y,headstocl on. said base, and means.

driven from a' common source of 'powerfo'rf operating said mechanisms to sim'iiltan'eous.-7V

`r8In a grinding machine,

substantially midway between the endstliereof, a pair of opposed headstoclrsv mounted on Y ,l said base at'opposite ends thereof Vand, slid-Y V thereof, each headstock, carrying a grinding wheel spindlewhichprojects 'from the inner end thereof toward'the opposed lieadstock, each spindle being mountable longitudinally ed initsheadstockfor rotationy about itsowil I i axis and about an axis eccentric to its own,

a motor carried byea.ch 'headstoclz,means for c driving the spindle of each"headstocli from the motor on the headstojck in all positions-of forl rotatingjeach spindle about its eccentric axis, a mechanism vjforv reciprocating each headstock oiisaidfbase, andv means including a! change.l Speed mechanismM for simultaneously driviiigsaic'l mechanisms andfor varying the, angularspeed of moveL f ment ,of each spindle about its eccentricy axis and proportionately varying thespeed fofre ciprocation thereof.

9. In a grinding ma base, a work support mounted ori-'saidl basej substantially` midway between the ends of,-a pair ofopposedliea'dstocls mounted on* said base at opposite ends thereofand slidable' longitudinally thereof, each headstock carthe spindle with respect to'saideccentricaxis,l;' i a mechanism loo chine, an elongated i therel ryinga grinding wheel spindle*which` pro-"y Y jects from the inner endjthereof towardth'e opposed headstoclr, each s'pindlebeing mount-j edin'its'headstock vfor rotation about its own axis'andmaboutan axiseccentric to its own,a` t' motor carried by each headstocln-'ineans'for *l driving the spindle 'of eachlieadstoclry from the motor on'the headstock in ally positions of the spindle with iespectto's'aid eccentric axis, aVV

mechanism for rotating each spindle about lv its eccentric axis, a mechanism, for 'reciprof4 eating each Vheadstock onsaid base,{ a drive 1 shaft,rdriving` connections for''simultaneously' driving said mechanisms froinv'said drive shaft, and a change speed mechanism ,interposed between 'said' vdrivey shaft.. andy said" 'the' speeds thereofy mechanisms for varying Y Y in relatively` small increments throughout :a relatively wide rangeoffspeeds. l

HENRY ifi. iriiiiitl f W'LLIAM J.' BAUMBERGER;

tures.

In testimony whereof we aiiix our signa?,VV Y 

